1. Field of the Invention
The field of the invention is that of connector sockets for electronic boards providing for both electrical and optical connection. These connectors are more specifically dedicated to aeronautical applications.
2. Description of the Prior Art
For a certain number of applications, it is necessary to provide, between units or electronic computers, both electrical links and optical links. These links are set up using a mix of optical and electrical connectors. These connectors comprise a plug and a socket. The plug is attached to the link cable interlinking the optoelectronic devices or the computers, and the socket is normally soldered directly onto an electronic board by means of electrical contacts, also called pins.
To produce this connector, the device represented in FIG. 1 is normally used. A socket 1 is mounted on a printed circuit 4, also called PCB, standing for Printed Circuit Board. This circuit comprises electronic components 5. A plug 2 comprising both electrical contacts and optical contacts provides the link between the socket and a link cable 27 comprising electrical cables 28 and optical fibers 29. In FIG. 1, the socket 1 and the plug 2 are shown separated for clarity.
This socket 1 comprises a mechanical frame 10 comprising seats with electrical and optical contacts, 7 and 8. This socket 1 is secured to the printed circuit 4 by mechanical means which also provide the electrical link. The means shown in FIG. 1 are, by way of example, small conductive columns 9. It is also fixed to the frame 3 of the computer. The electrical links with the electrical tracks of the circuit are provided by means of conventional electrical contacts 7, also called pins, soldered onto the circuit 4. The optical contacts are of fiber type, which means that a fiber segment 8 is linked on the one hand to the socket 1 and on the other hand to an optical output of an optoelectronic conversion module 6 handling the transduction of the optical signals into electrical signals. This module can be used either to transmit, or to receive, or to transmit/receive the optical signal. It is joined to the circuit 4. The optical output of the conversion module can comprise either an optical connector, or a fiber segment directly linked to the internal optoelectronic conversion devices of the module. The module is then said to be “pigtailed”. The first solution, which allows the fiber to be fitted and removed easily, is more commonly preferred over the second. It is used, in particular, with LC type optical connections.
The major drawbacks of this connection technique are, on the one hand:                the problems of securing the optical fibers leaving the socket, given the vibratory or impact-prone environmental conditions that can be extremely severe for computers on board aircraft;        the space occupied by said fibers. In practice, for the propagation of the light to be possible without significant losses inside the optical fiber, its bending radius must be greater than a minimum value as can be seen in FIG. 1 where the fiber segment 8 has a large bending radius. Observing this bending radius adversely affects the overall footprint of the optoelectronic device, particularly when the latter is a flat screen display device.        
To overcome these drawbacks, the U.S. Pat. No. 5,930,428 filed by Rockwell proposes integrating the optoelectronic conversion function 6 in the socket 1 itself as indicated in FIG. 2. Thus, the socket 1 comprises no more than conventional electrical outputs 7 and the electrical outputs 71 of the conversion modules, outputs that can easily be soldered on the printed circuit 4. Thus, the problem of footprint of the socket is resolved. This solution does, however, have two drawbacks:                to maintain a reasonable footprint for the socket, the standard optoelectronic components are ill-suited. It then becomes necessary to use very large scale integration optoelectronic components that are very expensive.        Each application requires dedicated components suited to the fiber standards, the useful wavelengths and the transmitted powers.        